What is the stabilizer in the formula of PVC edge banding?

(1) The thermal stabilizer must be able to capture the autocatalytic HCl released by the PVC edge banding resin, or react with the unstable polyolefin structure produced by the PVC resin to prevent or reduce the decomposition of the PVC resin. In general, the properties, functionality and product requirements of the heat stabilizer selected in the formulation should be considered.

Barium cadmium stabilizer is a heat stabilizer with excellent performance. Widely used in PVC agricultural films. It is often combined with barium, cadmium, zinc, organophosphites and antioxidants.

Calcium zinc stabilizer can be used as a non-toxic stabilizer in food packaging, medical equipment and pharmaceutical packaging, but its stability is relatively low. When the calcium stabilizer is used in large amounts, the transparency is poor and it is easy to bloom. Calcium zinc stabilizers often use polyols and antioxidants to improve their properties. In recent years, calcium-zinc composite stabilizers for hard pipes have appeared in my country.

Organotin heat stabilizer has excellent performance and is an excellent variety for PVC hard products and transparent products. In particular, octyltin has almost become an indispensable stabilizer for non-toxic packaging products and PVC edge banding, but it is expensive.

Epoxy stabilizers are often used as secondary stabilizers. When this kind of stabilizer is used in conjunction with the barium cadmium calcium zinc stabilizer, it can improve the light and thermal stability. The disadvantage is that it is easy to bleed out. Polyols and organophosphites can also be used as secondary stabilizers

In recent years, rare earth stabilizers and hydrotalcite stabilizers have also appeared one after another. The main feature of rare earth stabilizers is excellent processing properties, while hydrotalcite is a non-toxic stabilizer.

(2) During the processing and use of antioxidant PVC products, oxidation occurs due to the action of heat and ultraviolet light, and its oxidative degradation is related to the generation of free radicals. The main antioxidants are chain scission terminators or free radical scavengers. Its main function is to combine with free radicals to form stable compounds and terminate chain reactions. The main antioxidant of PVC edge banding is usually bisphenol A. There are also auxiliary antioxidants or hydrogen peroxide decomposers. PVC auxiliary antioxidants are triphenyl phosphite and benzene diisooctyl phosphite. The combination of primary and secondary antioxidants can work synergistically.